1. Field of the Invention
The present invention relates to fasteners, and more particularly to a fastener which can mount a thermal module onto a printed circuit board without risking damage to a heat generating electronic component disposed on the printed circuit board.
2. Description of Related Art
Thermal modules are traditionally used in micro-electronics to help transfer heat from heat generating electronic components mounted on a printed circuit board. The thermal module includes a heat sink, a heat pipe and a heat dissipating fan. The heat sink is located at an air outlet of the heat dissipating fan. The heat pipe has an evaporation section thermally contacting with the heat generating electronic component and a condensation section thermally contacting with the heat sink to transfer heat therebetween. The heat dissipating fan generates airflow which flows through the heat sink to take away heat therefrom.
In the thermal module, the evaporation section of the heat pipe is received in a groove of a casting die. The casting die is screwed to the printed circuit board to hold the evaporation section of the heat pipe in intimate contact with the heat generating electronic component. However, because the heat generating electronic component protrudes from a top surface of the printed circuit board, a space is formed between a bottom surface of the casting die and the top surface of the printed circuit board. In assembling of the casting die to the printed circuit board, it is difficult to control force exerted on the casting die and keep a proper space therebetween, so the evaporation section of the heat pipe can be held in intimate contact with but not damage the heat generating electronic component. However, excess force is always exerted on the casting die and this risks damaging the heat generating electronic component. Therefore, there is a need for providing a fastener which can make the evaporation section of the heat pipe to have an intimate contact with but not damage the heat generating electronic component.